Supplement to the
Fidelity® Mega Cap Stock Fund
Class A, Class M, Class C, Class I and Class Z
August 29, 2017
Prospectus

The following information replaces similar information found in the “Fund Summary” section under the “Fee Table” heading.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the fund or certain other Fidelity^® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 28 of the prospectus. Different intermediaries may provide additional waivers or reductions of the sales charge. Please see “Sales Charge Waiver Policies Applied by Certain Intermediaries” in the “Appendix” section of the prospectus.

The following information replaces similar information found in the “Fund Summary” section under the “Portfolio Manager(s)” heading.

Matthew Fruhan (lead portfolio manager) has managed the fund since April 2009.

Ashley Fernandes (co-manager) has managed the fund since October 2017.

The following information replaces the biographical information found in the “Fund Management” section under the “Portfolio Manager(s)” heading.

Matthew Fruhan is lead portfolio manager of the fund, which he has managed since April 2009. He also manages other funds. Since joining Fidelity Investments in 1995, Mr. Fruhan has worked as a research analyst and portfolio manager.

Ashley Fernandes is co-manager of the fund, which he has managed since October 2017. He also manages other funds. Since joining Fidelity Investments in 2008, Mr. Fernandes has worked as a global energy analyst, research analyst, and portfolio manager.

The following information supplements information found in the “Fund Services” section under the “Fund Distribution” heading.

The availability of certain sales charge waivers and discounts may depend on whether you purchase your shares directly from the Fund or through an intermediary. Intermediaries may have different policies and procedures regarding the availability of front-end sales load waivers or contingent deferred (back-end) sales load (“CDSC”) waivers. Please see “Sales Charge Waiver Policies Applied by Certain Intermediaries” in the “Appendix” section of the prospectus. In all instances, it is the purchaser’s responsibility to notify the Fund or the purchaser’s intermediary at the time of purchase of any relationship or other facts qualifying the purchaser for sales charge waivers or discounts. For waivers and discounts not available through a particular intermediary, shareholders will have to purchase Fund shares directly from the Fund or through another intermediary to receive these waivers or discounts.

The following information supplements information found in the “Appendix” section.

Sales Charge Waiver Policies Applied by Certain Intermediaries

Merrill Lynch

Shareholders purchasing fund shares through a Merrill Lynch platform or account are eligible only for the following load waivers (front-end sales charge waivers and CDSC, or back-end, waivers) and discounts, which may differ from those disclosed elsewhere in this prospectus or SAI.

Front-end Sales Load Waivers on Class A Shares available at Merrill Lynch:

Employer-sponsored retirement, deferred compensation and employee benefit plans (including health savings accounts) and trusts used to fund those plans, provided that the shares are not held in a commission-based brokerage account and shares are held for the benefit of the plan

Shares purchased by or through a 529 Plan

Shares purchased through a Merrill Lynch affiliated investment advisory program

Shares purchased by third party investment advisors on behalf of their advisory clients through Merrill Lynch’s platform

Shares of funds purchased through the Merrill Edge Self-Directed platform (if applicable)

Shares purchased through reinvestment of capital gains distributions and dividend reinvestment when purchasing shares of the same fund (but not any other fund within the fund family)

Shares exchanged from Class C (i.e. level-load) shares of the same fund in the month of or following the 10-year anniversary of the purchase date

Employees and registered representatives of Merrill Lynch or its affiliates and their family members

Directors or Trustees of the Fund, and employees of the Fund’s investment adviser or any of its affiliates, as described in the this prospectus

Shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within 90 days following the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a front-end or deferred sales load (known as Rights of Reinstatement)

CDSC Waivers on A, B, and C Shares available at Merrill Lynch:

Death or disability of the shareholder

Shares sold as part of a systematic withdrawal plan as described in the Fund’s prospectus

Return of excess contributions from an IRA Account

Shares sold as part of a required minimum distribution for IRA and retirement accounts due to the shareholder reaching age 70½

Shares sold to pay Merrill Lynch fees but only if the transaction is initiated by Merrill Lynch

Shares acquired through a right of reinstatement

Shares held in retirement brokerage accounts, that are exchanged for a lower cost share class due to transfer to certain fee based accounts or platforms (applicable to A and C shares only)

Front-end load Discounts Available at Merrill Lynch:

Breakpoints, Rights of Accumulation & Letters of Intent

Breakpoints as described in this prospectus

Rights of Accumulation (ROA) which entitle shareholders to breakpoint discounts will be automatically calculated based on the aggregated holding of fund family assets held by accounts within the purchaser’s household at Merrill Lynch. Eligible fund family assets not held at Merrill Lynch may be included in the ROA calculation only if the shareholder notifies his or her financial advisor about such assets

Letters of Intent (LOI) which allow for breakpoint discounts based on anticipated purchases within a fund family, through Merrill Lynch, over a 13-month period of time (if applicable)

AGII-17-06
1.885801.118

October 20, 2017